September weather forecastForest Grove, PA
September
Weather in September
The first month of the autumn, September, is still a warm month in Forest Grove, Pennsylvania, with temperature in the range of an average low of 57.9°F (14.4°C) and an average high of 76.1°F (24.5°C).Temperature
In Forest Grove, the beginning of September is marked by a marginally lowered average high-temperature, shifting from August's 82.8°F (28.2°C) to a still moderately hot 76.1°F (24.5°C). Forest Grove's nights in September cool down to an average low-temperature of 57.9°F (14.4°C).Humidity
In Forest Grove, the average relative humidity in September is 77%.Rainfall
The month with the least rainfall is September, when the rain falls for 12 days and typically collects 1.65" (42mm) of precipitation.Snowfall
In Forest Grove, snow does not fall in June through September.Daylight
In Forest Grove, the average length of the day in September is 12h and 27min.On the first day of the month, sunrise is at 6:28 am and sunset at 7:31 pm. On the last day of September, sunrise is at 6:56 am and sunset at 6:43 pm EDT.
Sunshine
The average sunshine in September in Forest Grove is 8.8h.UV index
The average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a medium vulnerability from unprotected exposure to Sun's UV rays for ordinary individuals.Note: The UV index of 4 during September leads to these advisories:
Be mindful. Individuals with a lighter skin tone may suffer burns in less than 30 minutes. When the Sun is at its strongest around midday, find shade and limit exposure. Wearing a wide-brim hat can block approximately 50% of UV radiation, protecting the eyes.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Forest Grove, PA
- Average high temperature in September: 76.1°F
The warmest month (with the highest average high temperature) is July (84.9°F).
The month with the lowest average high temperature is January (35.6°F).
- Average low temperature in September: 57.9°F
The month with the highest average low temperature is July (66.7°F).
The coldest month (with the lowest average low temperature) is January (23.4°F).
Average pressure in September
Forest Grove, PA
- Average pressure in September: 30.06"Hg
The month with the highest atmospheric pressure is November (30.12"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).
Average wind speed in September
Forest Grove, PA
- Average wind speed in September: 5.7mph
The windiest month (with the highest average wind speed) is March (8.3mph).
The calmest month (with the lowest average wind speed) is August (5.2mph).
Average humidity in September
Forest Grove, PA
- Average humidity in September: 77%
The months with the highest relative humidity are February and October (79%).
The month with the lowest relative humidity is April (73%).
Average rainfall in September
Forest Grove, PA
- Average rainfall in September: 1.65"
The wettest month (with the highest rainfall) is July (2.87").
The driest month (with the least rainfall) is September (1.65").
Average rainfall days in September
Forest Grove, PA
- Average rainfall days in September: 12 days
The month with the highest number of rainy days is July (17.3 days).
The month with the least rainy days is January (8.7 days).
Average snowfall in September
Forest Grove, PA
- Average snowfall in September: 0"
The month with the highest snowfall is March (2.76").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Forest Grove, PA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (7.9 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Forest Grove, PA
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 24min).
- Average sunshine in September: 8h and 48min
The month with the most sunshine is July (Average sunshine: 10h and 36min).
The month with the least sunshine is February (Average sunshine: 4h and 42min).
Average sunshine days in September
Forest Grove, PA
- Average sunshine days in September: 15.6 days
The month with the most sunshine days is November (18.5 days).
The month with the least sunshine days is June (11 days).
Average UV index in September
Forest Grove, PA
- Average UV index in September: 4
The months with the highest UV index are May, June, July and August (UV index 6).
The months with the lowest UV index are January, February, March, November and December (UV index 2).
Average cloud cover in September
Forest Grove, PA
- Average cloud cover in September: 38
The months with the most cloud cover are February and December (Cloud cover 48).
The month with the least cloud cover is July (Cloud cover 32).
Average visibility in September
Forest Grove, PA
- Average visibility in September: 5mi
The months with the highest visibility are January, February, March, April, June, July, August, October, November and December (6mi).
The months with the lowest visibility are May and September (5mi).





